Castleford Tigers have handed a “substantial fine” to Joe Westerman following an online video allegedly showing him involved in a sex act.
The club has also ordered the back-rower to help educate young people on the effects of alcohol and “dangers of social media when in the public eye”.
Westerman rejoined Castleford from Wakefield last year.
The 33-year-old said he wanted to “wholeheartedly apologise” to family and friends for his actions.
He added: “I’d also like to apologise to the supporters, sponsors, staff, and directors of Castleford Tigers as well as my team-mates.
“I’d like to extend this apology to the game of rugby league, and I have realised that I need to work on my decision-making around alcohol.”
Following an internal investigation, a club statement said: “The club and its welfare officers, in conjunction with Rugby League Cares, will continue to support Joe and his family throughout this difficult time and will make no further comment.”
The Tigers start the new Super League season with an away game against Hull FC on 19 February before taking on defending champions St Helens a week later.